These tests assume that PROPKA is installed as a module on your system the
dependencies in ../requirements.txt are satisfied.
If you are running in a virtual environment and want to make changes to your
code, module installation accomplished by
pip install -e .
from the top level of the PROPKA source directory.
Once PROPKA is available as a module, the tests can be run by
python -m pytest tests
either in the top-level directory or tests subdirectory.